Canterbury still finished second, meaning the two sides will contest a re-match in the major semifinal. However, with Wellington unable to play at the Basin Reserve due to scheduling conflicts, the game will be taken on the road at a likely neutral venue.
The loser of that clash will get a second chance against the winner of the minor semifinal, in which the red-hot Central Districts will host Northern Districts.
CD had won just one of their first six games to balloon out to 25-1 odds with the bookmakers, but their powerful squad have clicked into gear at the right time.
Their batting lineup is the strongest in the competition, and their bowling stocks had been recently replenished.
They needed to beat a just-as powerful Auckland side to qualify for the fourth and final playoff spot in a winner-takes-all encounter, and did one better with a bonus point victory jumping them into third spot on the ladder.
Auckland had the services of the returning Black Caps trio of Colin Munro, Lockie Ferguson and Colin De Grandhomme, and looked set for a big score at 203-3 with 17 overs remaining.
However, they collapsed to slump to 237 all out as George Worker (4-26), Ben Wheeler and Seth Rance gave CD a chance to chase the total down within 40 overs for a bonus point on the tiny Pukekura Park ground.
Jesse Ryder's 54 kick-started the chase, before Will Young and Tom Bruce took over.
With a win the first priority, they batted smartly in a partnership of 136, before reaching the stage where they needed 32 off 16 balls to claim the bonus point victory.
When Young (106* from 104 balls) brought up his century, Bruce (70* from 53) went bezerk, and CD required just nine balls for the required 32 runs to secure minor semifinal hosting rights.
The chase for quick runs was also relevant in ND's clash with Otago, with Otago needing a miracle to qualify for the playoffs.
Sent into bat, Northern posted 288-6, led by a superb display of straight hitting from Daryl Mitchell, who struck a clean 72 not out from 48 balls, after Ford Trophy rookies Nick Kelly (67 from 66) and Bharat Popli (69 from 97) set a solid platform.
Otago not only needed a bonus point, but they needed an unprecendented improvement in their net run rate, so they went about chasing the total with appropriately reckless abandon.
The majority of their batsmen came and went quickly, but Anaru Kitchen was at the other end compiling the innings of the summer.
Kitchen brought up his century from 59 balls, with Northern's best bowlers taking the brunt of his blows.
Scott Kuggeleijn went for 95 runs from his 10 overs, while Ish Sodhi took 4-85 off his 10 overs as Otago tried to go at a rate of 10 runs an over.
Kitchen finished his remarkable innings unbeaten on 143 from just 85 balls as Otago claimed a two wicket win with an astonishing 16 overs to spare, but it wasn't enough to leap them off the bottom of the ladder.
Northern Districts, Auckland and Otago all finished on 15 points, but ND claimed fourth spot due to the tiebreaker of most bonus points.
The playoffs begin on Saturday.
